What you need to know about basement sump pumps

During a heavy rainstorm or spring thaw, water can seep into a basement and flood it. To prevent this, many homes have a sump pump, which sucks water up and sends it out of the house. But is it the right solution for your house?

Depending on where you live and the age of your home, you may not have a sump pump in your basement. If you do, then typically:

• A sump pump sits in a tank, called a sump pit, that is installed at the lowest point of the basement floor.
• The walls of the sump pit are usually made of concrete, clay, tile or fibreglass.
• Water that collects around the foundation of the house is funnelled through weeping tile, and drainage rock channels it into the sump pit.
• When water fills the pit to a certain level, the pump is activated. It draws water out of the basin and discharges it through a drain with a check valve to prevent back flow.
• Sump pits are sold at lumberyards, home improvement centres, and large big-box retailers.

There are two basic types for home use:

• Submersible pumps are concealed in a sump pit, because they sit below the opening of the pit.
• In contrast, pedestal pumps sit tower-like on a column that protrudes out of the pit, holding the motor above the water.
• Both operate on electricity. Receptacles for sump pumps should be at least 1.2 metres (four feet) above the basement floor and protected by a ground fault circuit interrupter. Do not use extension cords with sump pumps!
• Both kinds of pumps draw water in through a filtered trap and pump it out of the basement through a discharge pipe.
• Most pumps are automatic, triggered by a float-operated switch when the water rises, shutting off when the water subsides.

Submersible pumps are recommended when the sump pit is near living areas, like a home office or rec room.

• Because they operate underground in the sump pit, they are quieter than the pedestal type since their noise is muffled.
• The downside is submersible pumps are more expensive and they are likely to wear out faster, because they are under water most of the time.

Pedestal pumps are noisier, but less expensive and easier to repair.

• A unit's cost depends on its pumping power in litres or gallons per minute.
• The least powerful pumps are cheapest to buy, but cost more to operate because they run more often and take longer to pump water out of a basement.
• Remember that the deeper your basement goes, the harder a sump pump will have to work to pump out water. It's fighting gravity, after all!

If well maintained, submersible pumps can potentially last from five to 15 years. On the other hand, pedestal pumps may last up to 25 years. To keep them going as long as possible:

• Clean and inspect the pump, inlet screen and the check valve yearly.
• If your sump pit routinely catches water from a dehumidifier or a washing machine, clean the filter more often and check that the float is not waterlogged or stuck.
• To test a pump, run water into the sump tank. The pump should run smoothly. If it sounds like it's working hard, or if it works slowly, unplug it, remove the inlet screen, then clean it.

The time you usually need a sump pump most is during bad or stormy weather, which is exactly when power is likely to be interrupted – meaning that the pump can't do its work. The solution?

• You can buy pumps with an auxiliary unit designed to operate when the primary cannot run.
• Auxiliary pumps operate on a rechargeable 12-volt battery.
• If your pump is protecting expensive flooring, a home office with computer wiring or important files at basement floor level, an auxiliary pump will give you peace of mind for a few extra dollars.

When the weather is bright and sunny outside, it's all too easy to forget that standing silently sentinel in your basement is a sump pump that might one day help prevent a soggy mess from ruining your basement and the possessions you keep in it.

While not every home needs a sump pump, if you have an older house or concerns about flooding, you may want to consider speaking with a plumber. He or she can help you decide if installing a sump pump, or upgrading the one you have, is right for your home.